Add support for userspace to push the video core clock to maximum supported by hardware. Change-Id: Ida6618fd77bc24fe043885306083249546797054 CRs-Fixed: 361108 Signed-off-by: Srinu Gorle <sgorle@codeaurora.org> [davidb: only include/linux/videodev2.h] Signed-off-by: David Brown <davidb@codeaurora.org>